I have PCOS and am trying to conceive so my Dr has sent me for some progesterone blood tests to detect ovulation. I have 3 months worth - the first blood test I did on day 20 of my cycle (not ovulating) and the second on day 24 (not ovulating), now I’m not sure what day of my cycle the third test should be done. The first test result on day 20 was slightly higher than the test on day 24. My cycles are a bit irregular but generally seem to be about 36-39 days long. Any help would be greatly appreciated!

Progesterone is a hormone that is made only after a woman ovulates and, in a spontaneous cycle, a progesterone >10 ng/ml indicates normal ovulation. Progesterone is best measured about 5 to 9 days before ovulation. Since a normal cycle interval is 26-32 days, measuring a progesterone on day 21 or 24 should be perfect. You described your cycle interval as occurring every 36-39 days. You are probably not ovulating but if you want to confirm this, please get your progesterone on around day 30. OK?